Defect-induced enhanced photocatalytic activities of reduced α-Fe₂O₃ nanoblades

Bicrystalline α-Fe₂O₃ nanoblades (NBs) synthesized by thermal oxidation of iron foils were reduced in vacuum, to study the effect of reduction treatment on microstructural changes and photocatalytic properties. After the vacuum reduction, most bicrystalline α-Fe₂O₃ NBs transform into single-layered NBs, which contain more defects such as oxygen vacancies, perfect dislocations and dense pores. By comparing the photodegradation capability of non-reduced and reduced α-Fe₂O₃ NBs over model dye rhodamine B (RhB) in the presence of hydrogen peroxide, we find that vacuum-reduction induced microstructural defects can significantly enhance the photocatalytic efficiency. Even after 10 cycles, the reduced α-Fe₂O₃ NBs still show a very high photocatalytic activity. Our results demonstrate that defect engineering is a powerful tool to enhance the photocatalytic performance of nanomaterials.